Due to the new approach of the scientists, old antibiotics will become safe and powerful drugs. The researchers around the world have been looking for chemicals that can improve human health. But evolutionary selection optimizes them not in favor of safety and effectiveness for humans. That discrepancy was inspiring for a group of the scientists at the University of Tokyo.
They intend to change wholesome natural products for safe human use. In the process of experiments, their idea was able to turn one of the oldest antibiotics on our planet into a new version of a modern, safe and powerful drug. Gramicidin A was originally identified in soil bacteria.
In the early 1940s, it became the first commercially produced antibiotic. Even today, doctors prescribe it to their patients, recommending it in the form of a cream or drops for some skin infections, for diseases of the eyes and throat, but it is strictly forbidden to use this drug in the form of tablets and injections. Gramicidin A kills bacteria by punching itself through the cell membrane. It causes the contents of the cell to leak out, allowing foreign particles to enter through nanoscale tunnels called ion channels.
They are unregulated and can cause significant damage to the body when gramicidin A is inside the body. The ion channel of gramicidin A fascinated scientists. These channels are involved in virtually all life processes, affecting brain function and blood pressure.
Over the past 80 years, about 350 artificial antibiotic analogs have been developed. All of them have similar initial data and therefore cannot be used on humans. But the scientists managed to find a use for it for human health. The researchers analyzed over 4,000 artificial analogs of gramicidin A. Each analog is a coil containing 15 amino acids, as well as the building blocks of peptides, which are short proteins.
Six amino acids were strategically selected to retain the main structural aspects of gramicidin A. Each of the six amino acids can be substituted for four different amino acids. It changes the way the peptides bind, resulting in 4096 variations.
Then the scientists used the synthesis method and it led to the formation of a completely new version of gramicidin A. It was tested for activity against streptococcus. As it turned out, the scientists received a new basis for a strong and safe drug that affects the viral structure, but does not affect the healthy cells.